Synthesis and Characterization of ZnO Micro-Tubes

2013 ◽  
Vol 678 ◽  
pp. 217-222
Author(s):  
Kugalur Shanmugam Ranjith ◽  
B.S. Kruthika ◽  
Ramasamy Thangavelu Rajendrakumar
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Tube Formation ◽  
Etching Time ◽  
X Ray Diffraction ◽  
Defect States ◽  
Photo Degradation ◽  
Growth Method ◽  
Koh Etching

ZnO microtubes were synthesized by two step process, (i) synthesis of ZnO microrods and (ii) etching the microrods to form microtubes. The ZnO microrods are synthesized by the simple solution growth method using the zinc chloride and hexamine as a precursors at around 95 °C. Using the KOH as the etchant the ZnO microrods have etched into ZnO microtubes. ZnO micro-tube formation was studied as a function of KOH concentration and etching time. At low KOH concentration the tubes were not completely etched whereas at higher concentration the tube walls were damaged. ZnO tubes were characterized by X-ray diffraction, scanning electron microscopy, UV-vis spectrophotometer and room temperature photoluminescence (PL) measurement. From the UV absorption spectra and PL spectra reveals the presence (Oxygen vacancies related) of defect states due to KOH etching. The as-synthesized Zinc Oxide micro tubes have a diameter of ~600 nm, wall thickness of 30–40 nm, and length of ~7 μm. ZnO microtubes were tested as the catalyst for the photo degradation of the methylene blue (MB) dye. The result shows the photo degradation efficiency of the tubes are twice faster compared to that of rods, this is due to high surface area associated with the tubes.

Synthesis and Characterization of Nanocrystalline Hydroxyapatite Powder

2015 ◽  
Vol 1087 ◽  
pp. 142-146 ◽  
Author(s):  
Rosli Asmawi ◽  
Mohd Halim Irwan Ibrahim ◽  
Azriszul Mohd Amin ◽  
Najwa Mustapha ◽  
Iis Sopyan
Keyword(s):  
Particle Size ◽  
Calcium Phosphate ◽  
High Surface ◽  
High Surface Area ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Heating Process ◽  
X Ray Diffraction ◽  
Nanocrystalline Hydroxyapatite

Nanocrystalline hydroxyapatite (HA) powder was synthesized by a simple heating process involving simple chemical reaction. The characterization of the produced powder showed that the powder is nanosize with particle in the range of 30-70 mm in diameter and almost evenly spherical in shape. The powder also has a high surface area of 43.16 m2/g. Field Emission Scanning Electron Microscopy (FESEM) observation showed the crystallite and particle size become bigger with an increment of calcination temperature, indicating increasing of crystallinity.. FESEM observation showed the particle size become bigger with an increment of calcinations temperature. It is in agreement with the crystallite size analysis, obtained by Scherer’s formula and particle size analysis, measured by nanoSizer. X-ray Diffraction (XRD) and Fourier Transform Infra Red Spectroscopy (FTIR) analyses exhibited the same result, where HA phase was clearly observed at at various temperatures up to 600 ̊C. However, at temperature more than 600 ̊C, Tri calcium phosphate (TCP) phase appeared suppressing the HA phase, producing biphasic calcium phosphate.

Synthesis and Characterization of ZrO2/Graphene Nanocomposite Materials

2012 ◽  
Vol 531 ◽  
pp. 161-164 ◽  
Author(s):  
Zong Hua Wang ◽  
Fu Qiang Zhu ◽  
Jan Fei Xia ◽  
Fei Fei Zhang ◽  
Yan Zhi Xia ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Transmission Electron ◽  
Ft Ir ◽  
Graphene Nanocomposite ◽  
Adsorption Desorption

Zirconia/graphene (ZrO2/graphene) nanocomposite has been successfully synthesized by a simple method. The as-prepared nanocomposite was characterized using transmission electron microscopy (TEM), FT-IR spectroscopy, power X-ray diffraction (XRD) and nitrogen adsorption-desorption. It was found that tetragonal ZrO2was uniformly deposited on graphene, which resulted in the formation of two-dimensional nanocomposite, it showed a high surface area of 165 m2/g.

scholarly journals Fabrikasi Nanotubes Titanium Dioksida (TiO2) Menggunakan Metode Hidrotermal

2017 ◽  
Vol 3 (1) ◽  
pp. 20-26
Author(s):  
Atik Setyani ◽  
Emas Agus Prastyo Wibowo
Keyword(s):  
Tio2 Nanoparticles ◽  
Tio2 Nanotubes ◽  
Crystal Size ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Nanotubes received great attention because it has a high surface area. In this study, TiO2 nanotubes fabricated via hydrothermal method from  synthesis of TiO2 nanoparticles via sol-gel method. Catalysts that have been synthesized later in the characterization by X-Ray Diffraction (XRD) to obtain the crystal size and crystallinity. Crystal size of TiO2 nanoparticles at a temperature of 450C is 13.78 nm. Then characterized by Transmission Electron Microscopy (TEM) to look at the formation of nanotubes. Characterization of TiO2 nanotubes with TEM shows that the structure of the tubes had already been formed TNTs although the growth has not been perfect. It can be seen from the structure TNTs who tend to be short and yet so irregular.DOI: http://dx.doi.org/10.15408/jkv.v0i0.5036  

High Surface Area Silicon Carbide Doped with Zirconium for use as Heterogeneous Catalyst Support

1996 ◽  
Vol 454 ◽  
Author(s):  
Marc J. Ledoux ◽  
Cuong Pham-Huu ◽  
Christophe Bouchy ◽  
Pascal Del Gallo ◽  
Claude Estournes ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
High Surface ◽  
Catalyst Support ◽  
High Surface Area ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Bet Method ◽  
Porosity Measurements

ABSTRACTHigh surface area (> 100 m2 · g−1) SiC doped with zirconium was prepared by the gas-solid reaction. The material was made up of three phases: β-SiC, covered by ZrO2 and an amorphous phase composed of Si, Zr and O. The characterization of the sample was performed by means of powder X-ray diffraction (XRD), surface area and porosity measurements by the BET method, scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). Preliminary catalytic tests, the standard n-C7 isomerization on supported MoOxCy showed that this new support was at least as effective as pure SiC.

scholarly journals Attached β-cyclodextrin/γ-(2,3-epoxypropoxy) propyl trimethoxysilane to graphene oxide and its application in copper removal

2017 ◽  
Vol 75 (10) ◽  
pp. 2403-2411 ◽  
Author(s):  
Zongxue Yu ◽  
Qi Chen ◽  
Liang Lv ◽  
Yang Pan ◽  
Guangyong Zeng ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Esterification Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cavity Structure ◽  
Optimum Ph ◽  
Exchange Adsorption ◽  
Langmuir Isotherm Model

The environmental applications of graphene oxide and β-cyclodextrin (β-CD) have attracted great attention since their first discovery. Novel nanocomposites were successfully prepared by using an esterification reaction between β-cyclodextrin/γ-(2,3-epoxypropoxy) propyl trimethoxysilane grafted graphene oxide (β-CD/GPTMS/GO). The β-CD/GPTMS/GO nanocomposites were used to remove the Cu2+ from aqueous solutions. The characteristics of β-CD/GPTMS/GO were detected by scanning electron microscopy (SEM), Fourier transform infrared, X-ray diffraction (XRD), thermogravimetric analysis (TG) and energy dispersive X-ray (EDX). The dispersibility of graphene oxide was excellent due to the addition of β-CD. The adsorption isotherms data obtained at the optimum pH 7 were fitted by Langmuir isotherm model. The excellent adsorption properties of β-CD/GPTMS/GO for Cu2+ ions could be attributed to the apolar cavity structure of β-CD, the high surface area and abundant functional groups on the surface of GO. The adsorption patterns of β-CD/GPTMS/GO were electrostatic attraction, formation of host-guest inclusion complexes and the ion exchange adsorption. The efficient adsorption of β-CD/GPTMS/GO for Cu2+ ions suggested that these novel nanocomposites may be ideal candidates for removing other cation pollutants from waste water.

Fabrication and repair of GaN nanorods by plasma etching with self-assembled nickel nanomasks

2021 ◽  
Author(s):  
Shiying Zhang ◽  
Lei Zhang ◽  
Yueyao Zhong ◽  
Guodong Wang ◽  
Qingjun Xu
Keyword(s):  
Inductively Coupled Plasma ◽  
Average Diameter ◽  
Etching Time ◽  
X Ray Diffraction ◽  
Plasma Etch ◽  
Inductively Coupled ◽  
Icp Etching ◽  
Self Organized ◽  
Gan Film ◽  
Koh Etching

High crystal quality GaN nanorod arrays were fabricated by inductively coupled plasma (ICP) etching using self-organized nickel (Ni) nano-islands mask on GaN film and subsequent repaired process including annealing in ammonia and KOH etching. The Ni nano-islands have been formed by rapid thermal annealing, whose density, shape, and dimensions were regulated by annealing temperature and Ni layer thickness. The structural and optical properties of the nanorods obtained from GaN epitaxial layers were comparatively studied by high-resolution X-ray diffraction (HRXRD), Raman spectroscopy and photoluminescence (PL). The results indicate that damage induced by plasma can be successfully healed by annealing in NH3 at 900 °C. The average diameter of the as-etched nanorod was effectively reduced and the plasma etch damage was removed after a wet treatment process in a KOH solution. It was found that the diameter of the GaN nanorod was continuously reduced and the PL intensity first increased, then reduced and finally increased as the KOH etching time sequentially increased.

scholarly journals USE OF MONTMORILLONITE CLAY FOR ADSORPTION MALACHITE GREEN DYE

2019 ◽  
Vol 16 (32) ◽  
pp. 279-286
Author(s):  
Marcos Antônio KLUNK ◽  
Zeban SHAH ◽  
Paulo Roberto WANDER
Keyword(s):  
Malachite Green ◽  
Retention Time ◽  
High Surface ◽  
High Surface Area ◽  
Exchange Capacity ◽  
Montmorillonite Clay ◽  
Malachite Green Dye ◽  
Low Levels ◽  
High Concentrations

Removal of malachite green dye by adsorption from aqueous solution using montmorillonite clay is reported in this work. A malachite green dye is a cationic widely used in textile industries. Due to its persistence in the aquatic environment, it becomes a problem for aquatic and terrestrial organisms. This dye can be adsorbed through various techniques, but high acquisition and operating costs preclude widespread use. Several adsorbents are available in the market, but the most outstanding are the clays, especially the montmorillonites. These clays are finely divided material ( 0.002 mm), and its adsorption properties are continuously investigated. Types of clays 2:1 (two tetrahedral to one octahedral) are called expandables. The montmorillonite has a potential for dyes removal in wastewater due to the high surface area, porosity with excellent cation exchange capacity conferring its adsorbent property. This work aims to use the montmorillonite as an adsorption system in stages to textile decolorization effluent, composed of malachite green dye, reproduced in the laboratory. The characterization of the clay gives high purity and is used as adsorbent of good quality and efficiency. The retention of dyes in the system composed of montmorillonite arranged in separation stages was efficient. The effect of dye concentration and retention time are the most important parameters used in this study. High concentrations and retention time below 24 hours resulted in low levels of removal (25%). On the other hand, the low level of initial concentration increases removal efficiency (57%). Thus, the results obtained in this work allow concluding that montmorillonite is able to removal malachite green dye.

scholarly journals Preparation and characterization of activated carbons from albizia saman pod

2017 ◽  
Vol 36 (3) ◽  
pp. 44-53
Author(s):  
G. D. Akpen ◽  
M. I. Aho ◽  
N. Baba
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Activated Carbons ◽  
High Surface ◽  
High Surface Area ◽  
Volatile Matter ◽  
Sieve Analysis ◽  
Albizia Saman ◽  
Temperature Surface

Activated carbon was prepared from the pods of Albizia saman for the purpose of converting the waste to wealth. The pods were thoroughly washed with water to remove any dirt, air- dried and cut into sizes of 2-4 cm. The prepared pods were then carbonised in a muffle furnace at temperatures of 4000C, 5000C, 6000C ,7000C and 8000C for 30 minutes. The same procedure was repeated for 60, 90, 120 and 150 minutes respectively. Activation was done using impregnationratios of 1:12, 1:6, 1:4, 1:3, and 1:2 respectively of ZnCl2 to carbonised Albizia saman pods by weight. The activated carbon was then dried in an oven at 1050C before crushing for sieve analysis. The following properties of the produced Albizia saman pod activated carbon (ASPAC) were determined: bulk density, carbon yield, surface area and ash, volatile matter and moisture contents. The highest surface area of 1479.29 m2/g was obtained at the optimum impregnation ratio, carbonization time and temperature of 1:6, 60 minutes and 5000C respectively. It was recommended that activated carbon should be prepared from Albizia saman pod with high potential for adsorption of pollutants given the high surface area obtained.Keywords: Albizia saman pod, activated carbon, carbonization, temperature, surface area

Sign in / Sign up

Export Citation Format

Share Document